Mohindar S. Puar

Wiedendiol-A and -B, cholesteryl ester transfer protein inhibitors from the marine sponge Xestospongia wiedenmayeri

Abstract Wiedendiol-A and -B, novel sesquiterpene-hydroquinones which inhibit cholesteryl ester transfer protein (CETP), have been isolated from the marine sponge Xestospongia wiedenmayeri. Additional related marine natural products were also evaluated for CETP inhibition. Compounds that inhibit the activity of CETP may find utility as antiatherosclerosis therapy.

Structure of Sch 68631: A new hepatitis C virus proteinase inhibitor from Streptomyces sp.

Abstract A novel hepatitis C virus (HCV) proteinase inhibitor, Sch 68631 ( 1 ), was isolated from the fermentation culture broth of Streptomyces sp. The structure of 1 was elucidated by analyses of spectroscopic data and shown to be a new member of the phenanthrenequinone family of compounds.

A novel class of antitumor metabolites from the fungus Nattrassia mangiferae

Abstract Sch 49210, Sch 53514 and Sch 53516 have been isolated from a fungal culture, and identified by analysis of 2D NMR data. Two diacetylation derivatives Sch 53515 and Sch 53517 have been synthesized. These compounds demonstrate inhibitory activity of phospholipase D (PLD), and display potent activity in the antitumor invasion chamber assay.

Two novel diketopiperazines isolated from the fungus Tolypocladium sp.

Abstract Diketopiperazines, Sch 54794 and Sch 54796, have been isolated from a fungal fermentation. The structures of these compounds have been established based on spectroscopic data analysis. Sch 54794 exhibited inhibitory activity in the platelet activating factor (PAF) assay.

A new fungal metabolite, Sch 202596, with inhibitory activity in the galanin receptor GALR1 assay

Abstract A novel spirocoumaranone, Sch 202596 ( 1 ), was isolated from the fermentation broth of Aspergillus sp. The isolation, structure elucidation and stereochemistry of 1 are described.

A novel microbial metabolite, activator of low density lipoprotein receptor promoter

The organic extract of the fermentation broth of a Micromonospora microorganism was found to contain SCH 351448 (1), the monosodium salt of a macrocyclic dilactone containing two identical diacids. The structure and relative stereochemistry were established by single-crystal X-ray analysis. SCH 351448 is a novel ionophoric compound and is a weak activator of low density lipoprotein receptor (LDL-R) promoter with an IC50 of 25 μM.

Isolation and structure of SCH 351633 : A novel hepatitis C virus (HCV) NS3 protease inhibitor from the fungus Penicillium griseofulvum

A new hepatitis C virus (HCV) protease inhibitor designated as Sch 351633 (1) was isolated from the fungus, Penicillium griseofulvum. Structure elucidation of 1 was accomplished by analysis of spectroscopic data, which determined compound 1 to be a bicyclic hemiketal lactone. Compound 1 exhibited inhibitory activity in the HCV protease assay with an IC50 value of 3.8 microg/mL.

A depsipeptide fungal metabolite inhibitor of cholesteryl ester transfer protein

The organic extract of the fermentation broth of a fungus was found to contain a depsipeptide SCH 58149 (1), containing three amino acids and a beta-hydroxy acid, by spectroscopic studies. The amino acids were phenyl alanine, alanine and leucine and the beta-hydroxy acid is 3-hydroxy-4-methyl octanoic acid. SCH 58149 exhibited weak activity against cholesterol ester transfer protein (CETP) with an IC50 of 50 microM.

Synthesis of E- and Z-Pyrazolylacrylonitriles and their evaluation as novel antioxidants

A facile synthesis of (Z)- and (E)-2-(5-arylpyrazol-3-yl)-3-(pyrrol-2-yl)acrylonitriles and (Z)-2-(1,3-diarylpyrazol-5-yl)-3-pyrrol-2-yl)acrylonitriles, and isomerisation of (Z)-2-(5-arylpyrazolyl)acrylonitriles to (E)-2-(5-arylpyrazolyl)acrylonitriles under basic conditions have been reported. (Z)-2-(1,3-Diarylpyrazolyl)acrylonitriles did not undergo isomerisation under the similar conditions. New compounds were identified on the basis of their spectral data (1H-, 13C-, 1H-1H COSY, NOESY, NOE, HMQC NMR, IR, UV and EI mass). The structures of one acrylonitrile and five of their precursor 6-arylpyran-2-ones and cyanomnethylpyrazoles were confirmed by X-ray crystallographic studies. Effects of pyrazolylacrylonitriles and their precursors on rat liver-microsomal lipid peroxidation were evaluated in vitro with a view to establish structure activity relationship and to identify a lead compound.

Synthesis and chemistry of thia-analogs of the anti-mitotic podophyllium lignans

Abstract The Michael-aldol product (8) from PhSH-PhCHO-2(5H)-furanone is converted by acids to the tricyclic compound (9), without the intermediacy of the olefin (10). The podophyllotoxin analog (22) was similarly obtained. The all-trans compounds were isomerised by DBU to the cis lactones. Hydroxylated analogs (26) and (33) were produced by reacting 2-(5H)-furanone with appropriate 2-mercaptobenzophenones. Thermal rearrangement of the sulfoxide (35) initially gave the spirocyclic isomer (37), then formed dimeric products on prolonged heating.